When the detective shows Special Agents' Bell and Zidan the license plate on the car, the back of the car is immaculate, despite having been smashed hard from behind.
Not only do Jubal, Maggie and OA forget to retrieve evidence from Jubal's friend even though they all saw him receive two baggies, but at the end, Jubal rinses it down the sink. This was an FBI undercover operation and that was evidence; if a real agent first forgot to retrieve the evidence right after the op, and then went to retrieve it, yet came back empty handed, they would likely be fired, or at least suspended, and put under investigation-especially if they are an addict.